Having already locked up Giancarlo Stanton through at least 2020, the Marlins have secured the services of an even younger core player. Christian Yelich, their 23-year-old leftfielder, has agreed to a seven-year extension worth $49.57 million. It's the second-largest extension for a player in his service class, and it marks further evidence that the Marlins are trying to build around a stable cast of players.

The 23rd pick of the 2010 draft out of Westlake High School in California, Yelich debuted for the Marlins on July 23, 2013 and made a solid showing as a 21-year-old rookie, batting .288/.370/.396 with 10 steals in 62 games. He extended a similar performance across his first full season, batting .284/.362/.402—good for the same 112 OPS+ as the year before—with nine homers and 21 steals. Batting primarily in the leadoff spot, he scored 94 runs, the highest total by a Marlin since Dan Uggla scored 100 in 2010.

Additionally, Yelich excelled in leftfield, with defense valued at 13 runs above average by both Defensive Runs Saved and Ultimate Zone Rating (he was -3 in sporadic centerfield play) en route to 3.6 Wins Above Replacement and a Gold Glove award. It was the first Gold Glove won by a Marlins player since pitcher Mark Buehrle in 2012 and the first by a Miami position player since '05, when Luis Castillo and Mike Lowell both took home trophies. In an interesting twist, Lowell, who is now an MLB Network employee, first broke news of the extension.

The annual breakdown of the deal has yet to be reported, but presuming that it incorporates this season—during which Yelich is making $570,000—it will run through 2021, with a $15 million club option and a $1.25 million buyout for '22, his age-30 season. Had he not signed, Yelich would have been eligible for arbitration after the '16 season and for free agency after the '19 season. His deal falls shy of the seven-year, $58 million extension to which Andrelton Simmons agreed last year, the largest for a player with between one and two years of service time, but it beats all other comers in that service class according to data at MLB Trade Rumors:

That's good company, of which only the extension of Gyorko—who suffered through a miserable season marked by plantar fasciitis last year—hasn't worked out, though of course it's early in most of those deals.

Via the Sun-Sentinel’s Juan C. Rodriguez, Yelich is just the third homegrown Marlin to receive a contract of at least four years since owner Jeffrey Loria bought the team in 2002, following Josh Johnson (four years and $39 million in '10) and Stanton. His deal is the second-longest in team history behind Stanton's record-setting 13-year, $325 million deal, topping the six-year, $70 million extension that Hanley Ramirez signed in '08. Johnson and Ramirez were both traded as part of the teardown of the free agent-laden '12 team.

Given that the opt-out in Stanton's deal comes after 2019, his age-29 season, the Marlins now have club control over two-thirds of their outfield through the remainder of their 20s. Currently, no other Marlin is signed past '16, but with these moves apparently representing a change in the way Miami does business, more extensions could be on the way. Back in December, CBS Sports’ Jon Heyman reported that the team had made long-term offers to ace Jose Fernandez, shortstop Adeiny Hechavarria and centerfielder Marcell Ozuna, but thus far things have been quiet on those fronts.

Based on the track record of agent Scott Boras, it's highly unlikely that the 22-year-old Fernandez, who's currently recovering from Tommy John surgery, will agree to an extension, but if he did, it would likely top that of Yelich. Fernandez has two years of service time, meaning that he can be arbitration eligible after this season and a free agent after '18—both consequences of the team opening the '13 season with him on the roster instead of keeping him down in the minors to start the year, as the Cubs may do to Kris Bryant.

Likewise, Ozuna, who's about 13 months older than Yelich, is a Boras client. As a Super Two, he'll be eligible for arbitration after the 2015 season and free agency after 2019. The soon-to-be–26-year-old Hechavarria will be arbitration eligible after this season and a free agent after 2018. Pitchers Henderson Alvarez and Steve Cishek and second baseman Dee Gordon could also be extension targets. Alvarez, who turns 25 on April 18, is making $4 million in his first year of arbitration eligibility this season; he can be a free agent after the '17 season. Cishek, who is 28, is making $6.65 million this season, with two more years of arbitration eligibility remaining as a Super Two. Gordon, who was acquired from the Dodgers in December, is also a Super Two; he turns 26 on April 22 and is making $2.5 million in his first year of arbitration eligibility, with his free agency pending after the '18 season.

With Yelich joining Stanton in the fold, it will certainly be interesting to see how many of these other Fish take the bait, but even if not all of them do, the Marlins have secured another important piece of their future.